For example, Japanese patent No. 2760472 discloses a manipulated position detection device. The manipulated position detection device includes a square detection plate having a manipulated surface on which a user places a foot. The square detection plate has a detection surface on the opposite side of the manipulated surface. A load sensor is provided to each of the three sides or four sides of the detection surface. FIGS. 16A, 16B, and FIG. 17 show an example of the manipulated position detection device including four load sensors provided to four sides of the surface opposite from the manipulated surface. Load sensors 104-1 to 104-4 are laid under the surface of a distortion member 103 on the opposite side of a manipulated surface 102-1 of a detection plate (manipulated surface) 102. In the present example, the manipulated surface and a movement transmission surface of the distortion member 103 are not located in the same plane or are not located in planes at substantially equivalent (same) levels.
In the present example, a force F is applied at the angle θ relative to the direction perpendicular to the manipulated surface 102-1. In this case, application is deviated by the distance xd corresponding to the angle θ from the barycenter position calculated by a generally-known barycenter calculating method using the equations (2-1) to (2-3). Therefore, the deviation xd needs to be corrected using an additional detection unit in order to calculate the accurate barycenter position.